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How moisture tests do or do not indicate hidden mold contamination: this article provides an explanation of An explanation of the relationship between level of moisture and mold growth in common building materials like drywall and paneling.
The photo at page top shows three different mold genera/species, each occurring at a different elevation on this basement wall.

The probable
reason for these distinct areas of growth was that water on the basement floor soaked the bottom section of drywall while upper sections
were less wet, each attracting a different mold genera and species.

Moisture Gradients and Mold Growth on Drywall and Other Building Surfaces

This document describes how to find mold and test for mold in buildings, including how and where to collect mold samples using adhesive tape - an easy,
inexpensive, low-tech but very effective mold testing method.

This mold inspection procedure helps identify the presence of or locate the probable sources of mold reservoirs in buildings, and helps decide which of these need more
invasive, exhaustive inspection and testing.

This section explains that because different mold genera/species will grow on the same building material at different moisture levels,
it is easy to make a mistake in inspecting or testing mold in buildings by ignoring the light-colored but more problematic molds that
are often found higher on drywall above the more obvious "black mold" people see there. At MOLD LEVEL REPORTING we comment further on errors caused by failure to select a properly-representative area of a surface when collecting mold or dust samples.

Keep in mind that different molds like different moisture, temperature, and food.

One reason
that S. chartarum has been "over-reported" as a problem in some studies is that the
field "experts" didn't look for lighter molds, and maybe they didn't even carry a flash
light.

The photo (left) shows three tape samples being taken from different heights on a
laundry room wall. Three different mold species were found, one in each
area. Only the lowest black mold was obvious.

Watch out: In this wall test of three molds which were growing quite close together, I've marked each tape sample
so that you can see where it was on the wall.

#1 =Stachybotrys chartarum,

#2 = Ulocladium chartarum,

#3 = Aspergillus sp.. - it is this third mold which, in a larger quantity,
would be airborne and more likely to bother building occupants.

Yet nearly 100% of home owners and 80% of industrial hygienists and
90% of home inspectors who send mold samples to our lab are going to tape-sample only the "dark mold" on this wall.

Why are there three different genera/species on this drywall? Most likely because each of them prefers a different moisture level
in the paper which they're digesting.

I can generally track the mold genera up the wall as a function of the moisture gradients in
the wall. When a wall has been wet because of wet floor conditions, the drywall and in-cavity wall insulation will be wettest at
the wall bottom.

Be sure to review our notes above on use of lighting at Use of a flashlight to find mold
since if you don't know exactly how to use a flashlight, as simple as it seems, you're not going to find important light-colored
molds in buildings.

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The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.

Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.

Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.

Fifth Kingdom, Bryce Kendrick, ISBN13: 9781585100224, is available from the InspectAPedia online bookstore - we recommend the CD-ROM version of this book. This 3rd/edition is a compact but comprehensive encyclopedia of all things mycological. Every aspect of the fungi, from aflatoxin to zppspores, with an accessible blend of verve and wit. The 24 chapters are filled with up-to-date information of classification, yeast, lichens, spore dispersal, allergies, ecology, genetics, plant pathology, predatory fungi, biological control, mutualistic symbioses with animals and plants, fungi as food, food spoilage and mycotoxins.

OTHER IAQ ISSUES: How To Find and Address Other Indoor Air or Indoor Environment Contaminants Besides Mold

Mold or allergens may not be the only or even the main indoor environmental contaminant. Don't let media attention to mold
cause so much enviro-scare fear that other, possibly more urgent hazards go un-addressed.

Rodents, Mice, Squirrel Control - I find high levels of mouse and rodent dander, fecal dust, and urine-contaminated dust in some buildings,
and high levels of these materials in building insulation in those locations. If you have a mouse problem, particularly if mice and their waste (fecals or urine) are contaminating
the building HVAC or building insulation, may need both steps to clean up or remove infected materials and steps to stop an ongoing
rodent problem. If squirrels are a problem, the cleanup needs to include closing off entry openings into the building. Get some
help from a licensed pest control expert.